1. Field of the Invention
Embodiments of the present invention relate to a device for the cement augmentation of bone implants.
2. Description of the Related Art
Bone cement augmentation in bone surgery has been known for several years. This augmentation is applied in osteoporotic bones where bone anchoring means such as screws, pins, nails and so on, may not anchor rigidly.
According to the known technology, the bone cement is inserted into the bone and is suitable as an anchoring bed for subsequently inserted implants. With bone cement, every bone filling material is understood to be hardenable by means of polymer, hydraulic or according to other reaction mechanisms. These implants are inserted before the cement hardens such that the cement may add on adhere to and anchor the implants. The drawback of this known technology is the complicated application of the bone cement and the difficulty in determining the correct position of the implant within the cement composite.
In order to solve these problems, particular implants have been developed that allow an application of the cement after the implant is inserted into the bone. Typically, implants and, particularly screws, have been used which that comprise a cannulation wherethrough the cement may be filled into the bone. This technology, however, requires a high viscous cement that may be injected through the relatively small cannulation. Furthermore, the amount and the position of the cement in the bone may not be controlled sufficiently. Bone cements having a lower viscosity, which have significant biological advantages with regard to bone cements that are not resorbable and that harden at a high temperature, are not suitable for use with these adapted implants.
From DE-A-3 508 759 to TRONZO, for example, a hip screw is known that is provided with a central through bore, said through bore opening in an open screw tip and having sideward openings between the thread walls. By means of this hip screw, anchoring of the oversized and pointed thread in the bone can be achieved on the one side hand, and on the other side hand a strengthening of the weakened bone material can be achieved by means of injecting the bone cements through the central bore, allowing the bone cement to flow through the sideward openings. The main disadvantage of this technology is that no common bone implants may not be used but instead specially manufactured, costly and complicated implants (hip screw) are necessary.
On this point, embodiments of the present invention intend to remedy the disadvantages of the known technology. Embodiments of the present invention are based on the objective of providing a device by means of which the cement augmentation of existing and/or novel bone anchoring means (or other bone implants) may be simplified.